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Avoid winter manure application to retain nutrients, protect waters

  • 12/22/2016 12:01:00 PM
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DES MOINES – For some livestock producers, manure application is limited after Dec. 21. But all livestock and poultry producers can benefit by avoiding manure application on snow-covered ground. 

Runoff and nutrient loss are more likely when manure can’t be injected into the soil or incorporated into a field. Freeze and thaw cycles throughout winter can cause nutrients to runoff when snow melts. Keeping nutrients on the fields also protects streams. 

For animal producers with totally roofed (confinements) facilities, limits on applying liquid manure on snow-covered ground began Dec. 21. Confinement facilities with 500 or more animal units cannot apply liquid manure on ground covered with an inch or more of snow or 0.5 inch of ice. Generally, 500 animal units is equal to 1,250 finishing hogs; 5,000 nursery pigs; 500 steers, immature dairy cows or other cattle; or 357 mature dairy cows. 

Except in emergencies, state law limits liquid manure application from Dec. 21 to April 1 on snow-covered ground unless manure can be properly injected or incorporated. Producers must call the local DNR field office to report emergency applications before they apply.

Starting Feb. 1, liquid manure application on frozen ground is restricted.  

While the law affects confinements with liquid manure, open feedlots and poultry producers can help keep manure in place by using common sense and choosing application areas far from a stream, on flat land with little snow cover. 

All producers must follow setbacks from certain buildings and environmentally sensitive areas for surface application. 

Find more information on separation distances and manure application at Look for recommendations from the Iowa Manure Management Action Group on applying manure in winter at